Experimental Design

A student wanted to compare the transpiration rates of two different plant species at varying levels of humidity. The results are recorded in the fable shown. Each plant group was given the same amount of water and light throughout the investigation. Which procedure should have been performed to precent error in this investigation?

• One type of plant should have been tested.

• Fewer plants should have been included in each group.

• The percentage of humidity should have been kept constant.

• Both groups should have been tested in the same soil type at each humidity level.

Answer explanation

Both groups should have been tested in the same soil type at each humidity level to prevent error in the investigation.

Tags

NGSS.MS-LS2-1

Jordan wanted to test factors that would change the reaction rate of the enzyme catalase when breaking down hydrogen peroxide. He put a potato slice in hot water for 2 minutes, in vinegar for 2 minutes, and then tested the reaction with hydrogen peroxide. There was no reaction & Jordan concluded that the hot water denatured the enzyme. Should Jordan trust his results?

• Yes, because high temperatures can denature enzymes.

• No, because he did not leave the potato in the vinegar long enough

• Yes, because there was no reaction to the hydrogen peroxide

• No, because there were two independent variables in the experiment

Tags

NGSS.HS-PS1-5

One is testing fertilizers on tomato plants. In plant A, there is no fertilizer. In plant B, you are using one brand of fertilizer. In plant C, you are using a different fertilizer. Every week, the plants are measured to see which plant has grown the tallest.

Which is the control?

• The plant

• The Fertilizer

• The height of each plant

• The unfertilized plant

Aaron wanted to test the affect of different colored lights on plant growth. Put the procedures in the correct order to carry out this experiment.

• Put one tomato seed each in a pot with the same type of soil.

• Let grow for 50 days and then measure the height of each plant.

• Place one pot under yellow light, one pot under red light, one pot under blue light, and one pot with no light.

• Water each pot daily with 30mL of water.

• Repeat 5 times and average the height for each group

Tags

NGSS.MS-LS2-1

NGSS.MS-LS1-5

Which of the following is a characteristic of a good hypothesis?

• It is vague and general

• It is testable

• It is based on personal beliefs

• It cannot be proven wrong

Cameron wants to test the effect of antibacterial soap on bacteria growth. What would be a valid hypothesis for this investigation?

Tags

NGSS.HS-ETS1-2

Students wanted to know how plant growth would be affected when given different amounts of water. To setup the experiment, pea plants were potted in the same pots and given the same amount of sunlight. 2 plants received 1/2 a cup of water, 2 plants received 1 cup of water, and the last 2 plants received 2 cups of water daily.

• Independent Variable

• the same pots and the amount of sunlight

• Dependent Variable

• Plant growth

• Constants

• Amount of water

Tags

NGSS.MS-LS2-1

NGSS.MS-LS1-5

During an experiment, a scientist tests variables. The ​ (a)   variable can be changed by the scientist, who then uses​ the (b)   variable to assess whether there were any changes. During the experiment, they use a(n) ​ (c)   group to give their independent variable to and a(n) ​ (d)   group that they do not give their independent variable to.

• independent
• dependent
• experimental
• control

Aya wants to test if lemon juice will slow down apple browning. She cuts two slices of an apple and covers the apple slices with lemon juice. She leaves the apples on the counter for 24 hours and then measures the amount of browning on each apple. What was the error in her experimental design?

Tags

NGSS.MS-LS2-1

Maddie wanted to see if different types of fertilizer influence sunflower growth. What is the control group?

• type of fertilizer

• sunflower grown without fertilizer

• groups with different types of fertilizer

• amount of sun light

Tags

NGSS.MS-LS1-5